TRENTON, N.J. (AP) — New data on an experimental AIDS vaccine that failed to work show volunteers who got the shots were far more likely to get infected with the virus through sex or other risky behavior than those who got dummy shots.

The new details, released Wednesday by drugmaker Merck & Co., don't answer the crucial question of whether failure of the vaccine also spells doom for many similar AIDS vaccines now in testing.

And researchers weren't sure why more of the vaccinated volunteers wound up getting HIV than those who got dummy shots.